Valve-stem silencer



- l,535,583 G. B. DOBSON VALVE STEM SILENGER April 28 1925.

Filed Feb. 2 5. 1921 j ff/yl Paten-ted Apr. l28, v1925.v

UNITED @STA-'rss GAIL BOBDEN DOBSON, OF IOjS ANGELES, CALIFORNIA.

VALVE-SIEM S-ILENCEE.

vApplication led'February 23, 1921. Serial No. 447,015.

"To all whom tanni/y concer/1,5

Be it known that I, GAIL BORDEN DOB- BON, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles `and State of California, have invented new and useful Improvements in Valve-Stem l Silencers, and the following is suoli a full,

clear, and exact disclosure of the invention that 'anyone skilled in the art Vto which it appertains may make and use vthe same.

My invention comprises a valve silencer1 for internal combustion engines, and em- Avallve stem, and held yieldingly in contact with the valve actuating end of the rocker arm; and a member, formed of sound deadening material, retained `.within and by the s1eeve, to serve as a-cushion between the contacting faces of the valve stem and land the rocker arm.

In ,addition to eliminating the noise re- -isu'lting from this valve actuation by the rocker arm, the device serves to hold the push rpd in contact with its actuating cam, at all 'ftimes; andalso the rocker arm in such contact `with the push rod, lthat any looseness in the connections between these parts will be vtaken up, and the consequent l noise resulting therefrom eliminated.

VI have illustrated the preferred specific form of my yinvention in the accompanying drawings, and a full disclosure of its construction and operation will be found in the following specification, wherein reference is made to the drawings.

. In the drawings,Fig. 1 is a transverse section through a typical internal combustion motor, showing a yalve and its actuating mechanism, and my invention as applied thereto; Fig. 2 is an enlarged fragmentary vtransverse vertical .section through the valve of Fig. 1, showing it in closed position and 'the yrelative position of the rocker arm;

Fig. 3 is a View similar to Fig. 2, showing the valve in open position as actuated by the rocker arm; Fig. 4is a further enlarged fragmentary sectional view, taken as indicatedv by the line 44of Fig. 2, showing in detail the relative positions of the upper end of the valvestem, and the contact end of the rocker arm when the valve is closed; and Fig. 5 is a View similar to Fig. 4, taken as indicated by the line 5 5 of Fig. 3, showing the relative positions ofthe upper end of the valve stem and the contact end of the rocker arm, when the valve is opened thereby.

While I have statedthat my present invention is particularly applicable to use as a means for eliminating the clicking noises resulting from the rocker arm method of Val-ve actuation in internal combustion motors; and the following specification and acvcompanym'g drawings illustrating it are each drawn to illuminate such use and appli.- cation; 1t 1s nevertheless to be understood that the device 1S not necessarily limited io vsuch a restricted application, but may be utilized in'other fields, with equal success, where similar objects are to be accomplished;

Referring now to the drawings the nunormally rest in a seat 16, likewise formed. 4in the top ofthe cylinder 11.

The valve portion 13 is held normally seated in the seat 16, by the action of an eXpansile coil sprin 17, surrounding the stem 14, and confine .between the top of the outer cylinder wall 18 and a seat 19, mounted on the upper end of the stem 14. The valve spring seat 19 here shown is typical of the type commonly used on motors of this character, and comprises a cup-shaped portion 2O having a concentric aperture through its bottom 24,

through which the upper end of the valve stem extends; and an annular flange k21, eX- tending outwardly from the upper rim of the cup-shaped portion 20, forming the annular seat 22 in which the upper end of the medium yof spur gears 32 and 33, driven ests. The seat 19 is retained on spring 17 the upper end of the valve stem 14 by means y struction, the valve is held, normally seated by the action' of the spring 17 ,and is actuated inv its opening movement throughthe medium of a rocker arm 25, pivotally mounted, as at 26, on a suitable standard or support`27 on the top of the Cylinder block 11, this rocker arm being' actuated or oscillated through the medium .of a push rod 29, the upper end 29b of which engages the end 28, and the lower end 29a of which is `engaged by a suitable cam 30` rigidly mounted onpa cam shaft 31. The cam shaft 31 is rotated in the usual manner through the from the main crank shaft 34 of the motor. Thus it'- will be seen that rotation of the cam 30, and contacting with the end 29a ot the push rack 29, will raise the end 28 of the rocker arm upon its pivot 26, moving the end 35 down wardly and into contact with the upper end of the Valve stem 14, to unseat the valve 13 against the action of the spring 17.

lnorder that the valve portion 13 will seat perfectly in the seat 1,6, it is usual in motors of this type of construction, when the valve is closed, as shown in Fig. 1, Jfor the Ycontact tace 36 of the end 35, of the rocker arm 25, to be slightly spaced from the top face 37 of the stem 14, and'to accom# plish this it is generally necessary to have the pushsrod 29 pivotally connected, by a pin or other means, to the eird 28 of the rocker arm 25, and a coil spring (not shown) in connection with the push rod 29, tol"- hold it downwardly with its end 29a in constant contact \vitli the cam 30. To eliminate noise and too much lost motion the space between the faces 36 and 37 is ordinarily very slight` generally no more than the thickness of a sheet of letter paper, which space is very diflicult to maintain in proper adjustment,

owing to the constant wearing o'fparts, ex- A pans1on due to heat, and from other causes. J

With the use of my device, as will later appear, the space between the faces 36 and 37 canbe made a great deallarger than in ordinary practice,y thereby obviating` the necessity of frequent adjustments to main-` tain the slight space above mentioned, obviating the necessity of a pivotal pinconnec- *tion between the pin 28 and the upper end of the push-rod 29, and also permits the elimination of the aforementioned spring on the push rod 29 to hold the lpwer end 29u in contact with the cam 30.A Not only can the 'last mentioned structural features be eliminatedbut the allowance of a large space be- 25, causing it to oscillate tween the faces 36 and 3.7 will obviate the possibility of the valve portion 13 improperly seating in the seat 16 due to any slight derangement in the .adjustment of the push rod 29 and the rocker arm 25.

My invention comprises essentially the sleeve 38 slidably mounted on the upper end of the valve stem 14, the upper end of which is normally held inV contact with the face 36 of tlie rocker arm 25, by the action of an expa-nsib'le coil spring' 39 conned between the valve spring seat 19, and an annular flange 40 extending outwardly from the upper end of the sleeve 38. The sleeve 38 may be constructed o-any suitable ma terial, such as steel, brass, or the like, the l can pass downwardly over the pin 23; however, in some cases the cup-shaped portion 20 may be of sufficient depthto permit the sliding of the sleeve 38` on the stem 14 without coming in contact with the pins 23 in vwhich case the slots 41 can be omitted. The spring 39 may be formed in any desired manner, either to be confined between thev bottom 24 of the cup-shaped portion 20., and the flange 40, or as shown in the drawings toA rest upon the upper .portion of the seat 19, and be coniined between this poi'- tion and the flanges 40. In any event the spring 39 will be weaker than the valve spring 17. i

A shock absorbing and silencing disk 42, constructed of any suitable material such as fibre, rubber, or the like, is` retained within and by the sleeve 38, between the contact face 36 of the rocker arm 25 and the to) face 37 of the valve stem 14. This disk may be of any suitable thickness to accomplish the purpose of absorbing the ,shock and` eliminating the noise of contact between the faces 36 and 37, when thevmotor is'` in operation. The sleeve 38 being in contact'with theface 36 of the rocker arm 25 at all times, the ldisk 42 will be retained within the sleeve and in position at all times `to 4be interposed between the faces 36 and end of the sleeve portion 38 so this portion I f the faces 36 and 37 will never be great tto replace valvesA and rocker arms due to the usual wear caused by contact of the 'faces 36 and 37, it will only be necessary to replace the sleeve 38 and disk 42, or, in most cases, only necessary to replace the disk 42, thereby reducing to a minimum the cost of maintenance of these parts of the motor.

In actual operation the spring 39 supported on vthe valve stem 14 and holding the sleeve 38 in contact with the face 36 of the rocker arm 35, willl also hold the end 28 in contactl'with the upper end 29b of the push rod 29, andA also the end 29a in contact with 4the lcam 30, thereby obviating the necessity of a spring on the push rod 29 to hold the lower end in contact with the cam 30. Also by the exertion of this torce on the end of the rocker arm 25y the spring 39 will take up any looseness in the joints 'of the rockerarm 25 and the push rod 29, thereby eliminating any rattling noises resulting from such looseness, due to wear of the parts, in addition to eliminating the .noises resulting from contact betweenthe faces 36 and' 37 during operation of the motor. Furthermore, the greater space being permitted between the faces 36 and 37, due to my'improved device, the valve portion 13 will be permitted -at all times to properly seat in the seat 16, and

`will not be prevented from properly `functioning in this respect, due to any slight inaccuracies of adjustment'of the rocker arm 25 and its actuating parts. Where this slight space between the faces 36 and 37 has been heretofore made, to eliminate noises, the valve has beenpvery often prevented rom properly closing due entirely to this space being entirely taken up owing to expansion of the parts by heat. With my device it is 'perfectly clear that these imperfections of operation will' be entirely eliminated.

While I have described the preferred speciiic embodiment of my invention, I'vreserve to myself the right to make any changes or modifications in structure, which come within the scope of the following claims.

I-Iaving described my invention, I claim:

l. In a device of the character described,

the combination ot a member interposed between the valve stem and its actuating means to deaden the sound oit contact therebetween, means lmounted independently movable relative to the valve stem and its actuatingmeans to prevent lateral displacement of said sound deadening. member, and means to yieldingly hold said movable member in engagement with said actuating means.`

2. In a device of the character described, the combination of a member interposed between the valve stem and its opening means to deadenthe sound of contact therebetween, and means axially slidably mounted on the valve stem to prevent displacement of said member.

3. In a device of the characterv described,

the combination of a member interposedl be' tween the valve stem and its opening means to deaden the sound of contact therebetween, and means axially slidably mounted on the valve stem to prevent lateral displacement o said member.

4. .In a device of the character described, the combination of a member loosely interlposed between the valve stem and its opening, means to deaden the sound of contact therebetween, and means aXiallyelidably mounted on the valve stem to prevent dis placement of said member. l

5. In a device of the character described, the combination with a valve and rocker arm, of a member interposed between the valve stem and rocker arm to deaden the sound of contact therebetween, means slidably mounted on the valve stem to prevent displacement of said member, and yielding means to hold said sliding means in contact with the rocker arm.

6. In a device of the character described, the combination with a valve and rocker arm, of .a member interposed betweenv the valve stem and rocker arm to deaden the sound of contact therebetween, means slidably mounted on the valve stem to prevent lateral displacement of said member, and yielding means to hold said sliding means in contact with the rocker arm.\

. 7 In a device of the character described, the combination with a valve and rocker arm, of a member loosely interposed between the valve stem and 'rocker arm todeaden the sound voli contact,therebetween, means slidably mounted on the valve stem to prev vent displacement oit' said member, and

yielding means to hold said sliding means slidably'mounted on the valve stem to pre-,.v

vent lateral displacement o said member, and yielding means to hold said sliding means in contact with the rocker arm.

9. In a device of the character described the combination with. a valve and rocker arm, of a member interposed between the.'

. valve stem and rocker'arm to deaden the yielding' means to hold said sleeve in con,-`

taet with the rocker arm. A: t

10. 'In a device of the character described, the combination with a valve and rocker arm, of a member interposed between 'the valve stem and' rocker arm to deaden the sound 01"' Contact therebetween, saidmember being of. substantially thesame cross Sectional area as the valve stem, a sleeve member slidably mounted on the valve stem to prevent lateral displacement of said inember, and a spring t0 hold said sleeve in contact with the end of the rocker arm, said l igssmse spring being weaker than the valve spring.

11. In a device of. the character described, the combination with ye 'valve and rocker arm, of a member interposed between the valve stem and rocker arm to vdeaden the sound of contact therebetween, said mein-v be'r being substantially thesame. cross sectional area as the valve stem, a sleeve member slidablymounted on the valve stem to prevent lateral displacement of said member, and a spring mounted on the valve stem to hold said sleeve in contact with ther end of the rocker arm, said spring being weaker than the valve spring.` l

In witness that I claim the'foregoing I have hereunto subscribed my name this 14th day of February, 1921.

v GAIL BORDEN DOBSON. 

